Removable load bed for a vehicle

ABSTRACT

A loading apparatus for a vehicle, the apparatus having a first frame, a second frame having a chain mounted thereupon; and a locking system that is mounted on the first frame. The locking system has a drive wheel, a first arm member and a second arm member. The system is configured such that in a generally closed position, the chain engages the drive wheel in a first position, the drive wheel is connected to the arms; the arms are urged into the closed position. In a generally open position, the chain engages the drive wheel in a second position and the arms are urged into the open position by the second frame.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a division of U.S. patent application Ser.No. 09/493,478, filed Jan. 28, 2000, which is incorporated herein byreference in its entirety for all purposes.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to devices for loading and unloadingcontainers and more particularly, to a chain locking mechanism forsafely loading a movable frame onto a stationary vehicle.

2. Description of Related Art

A conventional cab and chassis vehicle when used to transport loadsusually comprises a frame and a device for pulling a movable frame fromthe ground up and over onto the vehicles' stationary frame, and guidingthe frame into the loaded position. During normal usage, the movableframe supports a load which is transferred from the ground to thevehicle chassis via an arrangement of elevating booms and guide systemsthat are controlled by an operator. This simple approach has manylimitations and there are many patents disclosing devices that simplifythe procedure and/or improve the safety aspects of such a maneuver.

U.S. Pat. No. 1,794,318 (Perkins et al.) discloses a dumping body frametruck that is driven by a chain drive. The body is formed by telescopicsections that are collapsed to dump a load. While the sections aredesigned to slide along the chassis body, there is no bed that isremovable from the chassis.

U.S. Pat. No. 2,811,269 (Anderson) discloses a removable bed that relieson a winch assembly to draw the truck body onto the chassis.

U.S. Pat. No. 5,203,788 (Marmur) discloses an apparatus for loading acontainer onto a truck body or trailer. This arrangement discloses theuse of a pivoting arm and a cable to move the trailer.

U.S. Pat. No. 5,269,746 (Zoromski) discloses a container loading andunloading system that is particularly suited for loading campers andcargo boxes onto a truck bed. The system appears to be independent ofthe vehicle except for a yoke and pivot bar structure that is attachedto the rear bumper.

U.S. Pat. No. 5,856,869 (Slokum et al.) discloses a removable load bedthat includes a tiltable bed that is operated by a piston to controlloading and unloading of the container. The system relies on a cable andbracket system to move the container. While the tiltable bed andinterlocking bracket and cavity aspect of this patent appear to addressdeficiencies that are present in the previously described patents, itstill suffers from the potential that the cable may come off thebracket, and therefore, could potentially be a safety hazard.

The frames of common conventional loading devices are generally similarin size and construction, and thus many of the loads that are to be usedwith such a frame arrangement tend to rely on a smooth and easy transferfrom the ground to the truck bed. It is often difficult to maintainadequate control of this maneuver, and thus inadvertent lateral movementand slippage of the pulling mechanism can occur, especially during theinitial lifting procedure.

Thus, there is a need for a removable load bed assembly for use with aconventional cab and chassis vehicle that provides a safe method oftransferring a load from the ground onto the chassis of the vehicle.This patent should not be limited to this only. Other examples aremilitary track and rubber tired vehicles that could have the bodieschanged from a gun carrier to personal carrier to an ambulance body.This system will lift any load from one level to another.

SUMMARY OF THE INVENTION

The invention reduces the difficulties and disadvantages of the priorart by providing a guide system, a simple chain locking assembly and adevice to control tilting action which can be retrofitted to mostconventional truck chassis at relatively low cost. The device provides asecure and simple means for loading a load onto a truck, thus reducingrelative movement therebetween.

The invention provides a loading apparatus for a vehicle, the apparatuscomprising:

-   a first frame;-   a second frame having a chain mounted thereupon; and-   a locking system mounted on the first frame, the system having a    drive wheel, a first arm member and a second arm member, the system    being configured such that:-   in a generally closed position, the chain engages the drive wheel in    a first position, the drive wheel being connected to the arms; the    arms being urged into the closed position; and in a generally open    position, the chain engages the drive wheel in a second position,    the arms being urged into the open position by the second frame.

In another aspect, the invention provides:

-   a third arm member;-   a stationary support member fixably mounted on the drive wheel, the    support member having a first end portion and a second end portion;    and-   a compressing member mounted on the support, the compressing member    being attached to the arms, the arms being urged towards each other    in the closed position-   wherein the first arm member and the second arm member interlock    with each other in the closed position.

In another aspect the invention provides the first arm member having aprojection extending outwardly therefrom, the arm member having a firstend portion and a second end portion, the first end portion being urgedtowards the chain, the second end portion being pivotally attached tothe first end portion of the support; the second arm member having afirst end portion and a second end portion, the first end portion beingurged towards the chain, the second end portion being pivotally attachedto the second end portion of the support member; and the third armmember having a first end portion and a second end portion, the firstend portion, the second end portion being pivotally attached to thesecond end portion of the support member. The third arm member has agroove disposed therein, the groove being shaped to cooperate with theprojection on the first arm member.

In yet another aspect, the invention provides the first frame furthercomprising: a front end portion and a rear end portion, the frame beingmounted on a vehicle chassis, a prime mover mounted on the chassis; andan axle connected to the drive wheel to alternatively move the drivewheel in a first and a second direction.

In another aspect the invention provides a loading frame comprising: thefirst frame as claimed as described above; an actuator; and anelevatable support to receive a load from the second frame and connectedto the actuator. The loading frame further including: a guide systemhaving a central rail shaped to cooperate with the second frame. Therail has a slidably resilient material fixably mounted thereupon.

In another aspect, the invention provides the second frame furtherhaving: a plurality of wheels such that the second frame is movablerelative to the first frame; a first rail, a second rail and a centralrail, the central rail being shaped so as to cooperate with the centralrail on the first frame.

In yet another aspect, the invention provides the second frame having afront end portion and a rear end portion, the front end portion beingdisposed towards the rear end portion of first frame.

BRIEF DESCRIPTION OF THE DRAWINGS

In drawings which illustrate embodiments of the invention,

FIG. 1 is a side view of a first embodiment of the invention showing amovable frame engaging a stationary frame on a vehicle via a chain;

FIG. 2 is a top view of the vehicle showing the stationary frameattached to the vehicle;

FIG. 3 is a rear end view of the rear block assemblies mounted on therear of the vehicle;

FIG. 4 is a simplified side view of the first embodiment showing therelationship between a rear block assembly and a frame rail;

FIG. 5 is a simplified view of the locking pin assembly;

FIG. 6 is a side view of the moveable frame;

FIG. 7 is a top view of the movable frame;

FIG. 8 is a simplified side view of the chain detail attached to themovable frame;

FIG. 9 is a simplified side view of the first embodiment in a lockedposition engaging the chain;

FIG. 10 is a simplified view of the first embodiment in a partially openposition showing the frame engaging the locking system;

FIG. 11 is a simplified side view of the first embodiment in a fullyopen position;

FIG. 12 is a simplified end-on view of the moveable frame loaded on thestationary frame showing the interlocking of the rail systems;

FIG. 13 is a schematic rear view of the first embodiment;

FIG. 14 is a front end view of the moveable frame;

FIG. 15 is a simplified view of the internal ramp and lift tab;

FIG. 16 is a schematic view of the stationary shoe showing shape;

FIG. 17 is a side view of the front end of the moveable frame;

FIG. 18 is a detailed side view of the stationary frame;

FIG. 19 is a detailed view of the elevatable support;

FIG. 20 is a detailed top view of the front of the moveable frame rail;and

FIG. 21 is a cut away side view of the movable frame shown in FIG. 7,balanced on the stationary frame shown in FIG. 2.

DETAILED DESCRIPTION

Referring to FIGS. 1 and 2, an apparatus according to a first embodimentof the invention is shown generally at 10 and connects a movable frame11 to a conventional cab and chassis vehicle 13 via a chain 66, theframe 11 having a load 100 securely mounted thereupon. The vehicle 13has a chassis 9 and a stationary frame 19 securely mounted thereupon.The stationary frame 19 is a “skeleton body” and is secured to thechassis 9 by conventional means, and is arranged such that a front endof the frame is disposed towards the rear of the cab of the vehicle 13and a rear end portion is disposed towards a rear end portion of thechassis 9.

The stationary frame 19 has a guide system mounted on the chassis 9 ofthe vehicle 13 and comprises a “skeleton-type” arrangement of rails 16.The rails 16 are positioned parallel to each other along the side of thechassis 9 and are shaped so as to allow efficient sliding and seating ofthe moveable frame 11 during loading and are coated with an ultra-highmolecular weight (UHMW) polymer 20. One skilled in the art willunderstand that polymers of this type act as a lubricant to assist themoveable frame 11 as it slides over the stationary frame 19, as will bedescribed below. It will be understood that there are many differenttypes of polymeric coatings used in this type of operation.

Referring to FIGS. 1, 2, 3, 12 and 18, an elevatable support 17 iscentrally and rotatably attached to an axle 14 and includes a “skeletonframework” 61 having a separate guide system 59 consisting of aforwardly disposed end and a rearwardly disposed end. The guide system59 consists of a C-shaped channel 54 with an internal ramp 33, and aslide rail 44. The slide rail 44 is covered with UHMW 50 on upper andlower faces. The skeleton framework 61 has two ends and a center that isparallel to the axle 14. The skeleton framework 61 ends are rotatablyattached to the axle 14 by a pair of bushings 106. The position ofskeleton framework 61 on the axle 14 is maintained by a pair ofcylindrical spacers 107. Each spacer 107 is positioned on the axle 14between the elevatable support bushings 106 and a pair of outer axlebearings 108. Those skilled in the art will recognize that bearings ofdifferent types may be used in place of the bushings 106 and spacers107. The axle 14 is rotatably mounted to the chassis 9 by the bearings108 and a bearing 122. Each bearing 108 is fixably attached to andlocated on the axle 14 adjacent the two end portions 21 and 55. Thebearings 108 are fixably attached to each of the chassis 9 frame rails.The bearing 122 is fixably attached and located in the center of theaxle 14 and is supported by the stationary frame 19. The axle 14 isdriven by an electric motor 94. Those skilled in the art will recognizethat other types of motors may be used to implement aspects of theinvention. The axle 14 has two end portions 21 and 55 that covers thefirst embodiment 10. The motor 94 is attached to the axle 14 by a keyedsprocket and an endless roller chain 104. The turning motion of the axle14 is transferred to a pair of keyed sprockets 12 that are mounted onthe ends of the axle 14.

The guide system 59 is aligned parallel to and between the frame rails16, and is fixably attached to the framework 61 such that a movableframe receiver 72 aligns and interlocks with the slide rail 44 when theframe 11 is mounted on stationary frame 19, as will be described. Thebottom edge of the rearwardly disposed section of the guide system 59 isfixably attached to the top edge of the center portion of the skeletonframework 61. A pair of support frame members, 111 and 112, are attachedto the guide system 59, and each having first and second ends. The firstend top edges of the support members, 111 and 112, are fixably attachedto the bottom edge of the forwardly disposed end of guide system 59,whereas the second ends are fixably attached to the corresponding endsof the skeleton framework 61. The support members, 111 and 112, supportthe forwardly disposed end of guide system 59, thereby ensuring theguide system 59 remains parallel with the frame rails 58 on the moveableframe 11. The top and bottom surfaces of the rail 44 are covered withUHMW 50.

As best seen in FIGS. 1, 2, 3 and 19, a hydraulic cylinder 46 isattached to the stationary frame 19 and is moved by a pair of arms, 15and 37, that are pivotally attached to the frame 19, a cross member 53and the forwardly disposed end of the guide system 59. The hydrauliccylinder 46 acts as a shock absorber during on-loading and off-loadingand also allows an operator to stop the tilting motion of the moveableframe 11 at any time thereby giving the system a greater degree ofcontrol during operation. It will be understood that other “damping”systems may be used with the elevatable support 17.

Also, those skilled in the art will recognize that the elevatablesupport 17 does not require arms 15 and 37 for the hydraulic cylinder46. Another possible method would be to use a longer cylinder therebyavoiding the use of the arms, 15 and 37.

As best seen in FIG. 21, the elevatable support 17 is pivotally attachedto the axle 14 that is positioned at the rear end of the vehicle 13. Themovable frame rail 58 pivots when loading or offloading on the surfaceof a slide 8 with the center of the circumference of the axle 14 beingthe center of the arc of the slide 8 (see FIG. 4). This creates a commonpivot point for both the receiver 72 on the movable frame 11 and theelevatable support 17 thereby ensuring both alignment and non-bindingmovement between the elevatable support 17 and the receiver 72 (see FIG.6) prior to interlocking and when interlocked. As best illustrated inFIGS. 2 and 19, a pair of springs 43 assist in lifting and holding theelevatable support 17 up by exerting a twisting force on a hinge pin 47that is fixably attached to the arm 15. The outer coils of the springs43 are attached to a bar 64 that is attached to the arm 37. Thistwisting action assists in opening the arms, 15 and 37, with the hingepin 47 as the center axis. The lifting and maintaining of the elevatablesupport 17 vertical position may be accomplished by placing the springsin other areas, for example, over the cylinder 46 or to the frame 19 andlifting under the arms, 15 and 37, below the hinge pin 47. Those skilledin the art will recognize other means of assisting the lift and holdingthe elevatable support.

Also, those skilled in the art will recognize that the elevatablesupport 17 does not require arms 15 and 37 for the hydraulic cylinder46. Another possible method would be to use a longer cylinder therebyavoiding the use of the arms, 15 and 37.

As seen in FIGS. 2, 3 and 4, the frame 19 has a pair of rear blockassemblies 80 generally located at the rear end of the frame rails 16 ofthe vehicle 13 and fixably attached to the chassis 9. Each rear blockassembly 80 consists of a slide arrangement 8 that is designed to evenlydistribute the load of the movable frame 11 during loading andunloading, and to distribute the overall weight of the loaded movingframe away from the sprockets 12 during the loading and unloadingprocess. As best seen in FIGS. 3 and 4, the axle 14, the sprocket 12,the elevatable support 17 and the slide arrangement 8 are co-axiallyarranged, ensuring the vertical alignment of the elevatable support rail44 with the receiver 72 (FIG. 12) while the slides 8, rails 16 and theframe rails 58 assume lateral alignment.

At the front end of the stationary frame is a locking pin assembly 82.As best seen in FIG. 5, the assembly 82 provides a manual positive locksystem when the movable frame 11 is fully loaded on the stationary frame19 and is a safety feature that prevents movement of the movable frame11 into the cab of the vehicle during an accident. A rod 74, is attachedto a first locking pin 71 and second locking pin 78, adjacent a handle89. The first pin 71 is moveable in the same direction as the rod 74.The second pin 78 is positioned away from the handle 89 and is attachedto a fulcrum plate 76 which reverses the direction of the rod 74 duringoperation. As the rod moves in a first direction, the first pin 71 movesin the same direction, whereas the pin 78 moves in a second direction.

As best seen in FIGS. 3, 4 and 6, a pair of stop plates 81 in the rearblock assembly 80, act as collision impact buffers to prevent themovable frame 11 from damaging the vehicle body when a movable framestop plate 67 abuts the stop plate 81. Furthermore, the stop plates 81and 67 allow precise location of the movable frame 11 on the frame 19and also allows for precise alignment of the locking pin assembly 82(see FIGS. 4, 5 and 12) on the frame 19 with a plurality of lock pinholes (not shown) on the movable frame 11. Slide 8 on the rear blockassembly 80 are coated with the UHMW 45 that acts as a lubricant toassist the movable frame as it slides over the rear block 80.

The rear block assembly stop plates 81 are positioned rearward of theaxle 14 yet forward of the most rearward teeth of the sprocket 12. Asseen in FIGS. 1, 7, 8 and 17, this allows a cross member 65 and a frontportion 25 of the rail 58 to be unobstructed by the stop plate 81 whenlifting or lowering moveable frame 11 when tag chains 66 and or links 62are engaged on teeth of the sprockets 12.

With the moveable frame 11 tilting backward, the front of the receiver72 tilts up, and with the receiver 72 and the slide rail 44 interlocked,the elevatable support 17 also moves up. The elevatable support 17 inturn pulls on the arms 15 by an arm pin 48. In turn, the arm 15 pulls onthe hinge pin 47 in turn pulling the lower arm 37 up with the lower endof the arms 37 connected to the sub frame cross member 1 with a hingepin 49. The arms 15 and 37 hinge open with hinging taking place on thehinge pin 47. This action extends the hydraulic cylinder 46 as the ram41 is connected to the arm 15 through the upper cylinder pin 39 and thebarrel of the cylinder 42 is connected to lower arm 37 by a lowercylinder pin 51. An operator can allow the moveable frame 11 to tiltwithout further forward and rearward movement if frame 11 is in anunbalanced condition.

Referring now to FIGS. 1, 6, 7, 12 and 14, the movable frame 11comprises a “skeleton body” type frame with a pair of longitudinal rails58 which act as slides so as to guide the rails 16 on the frame 19.Disposed between, and parallel to, the rails 58 is the receiver 72 whichis positioned across the under side of a plurality of cross members 77and along a portion of the frame 11 length. Mounted to the frame is theload 100 and a set of removable wheels 56 to allow movement. Thoseskilled in the art will recognize that other means for moving the frame11 are available to implement aspects of the invention, for example,skid plates. The movable frame 11 has a front end portion 25 and a rearend portion 27. The front end portion 25 is disposed toward the rear ofthe stationary frame 19 during initial maneuvering. The load 100 isattached to the frame 11 with the front portion 25 of the box 100positioned rearward of the front portion 25 of the frame 11. Thispositioning allows the movable frame 11, when on or off-loading, to belifted or lowered without the box 100 contacting the tag chains 66 orthe sprockets 12.

As best illustrated in FIGS. 1, 6, 8, 17, 20 and 21, the frame 11 has atag chain 66 that is attached to a roller chain 83. The roller chain 83is fixably attached to a roller chain frame 60, which in turn is fixablymounted to the frame 11. With the movable frame resting on level ground,the vertical distance between the bottom face of the portion of rail 58that slides on the top of slide 8 and the bottom of the roller on theroller chain 83 is equivalent to the distance between the radiuses ofthe slide 8 and bottom of valleys, between the teeth, of sprocket 12.These equivalent measurements allow the frame rail to slide over theslide 8 and the rail 58 support the heavier loads. The curved nose 123of the front portion of the rail 58 that slides over slide 8 is curvedto allow the rail 58 to slide over slide 8 when initially loading aheavily loaded frame 11. A first link 62 of the chain 83 is positionedadjacent lips 52 that are supported on the frame 11. The lips 52forwardly protrude from the roller chain frame 60 and over the top ofthe side plates of the link 62 and prevent the over stressing of theside plates. This reduces the possibility that the side plates may breakduring the lifting or lowering of the front portion 25 of the frame 11.One skilled in the art will recognize that the side plates are notdesigned for excessive force 90 degrees to the chain side plate. The tagchain 66 has an unattached end portion 63 that enables an operator toguide the tag chain 66 onto the sprockets 12 of the frame 19. Thesprockets 12 are positioned such that the unattached end portion 63 ofthe chain 66 can be engaged on the sprockets without hindrance fromother components. When the sprockets 12 are turned by the axle 14, thetag chain 66 is pulled tight in the direction of the wheels' rotationand serves to pull the loaded frame 11 toward and up onto the firstframe 19. When not in use, the tag chains 66 are pivoted up and back onto the top of roller chain frame 60. This advantageously protects thechain from damage. There is a corresponding storage track 84 on theframe 19 which also acts as a housing for the tag chain 66 when theframe 19 is fully loaded with the movable frame 11.

Referring now to FIGS. 2, 3, 7, 14 and 17, a plurality of disposedtie-down brackets 85 on the frame 19 permit locking of the movable frame11 to the frame 19 in the final loaded position. Disposed towards eachof the four corners of the movable frame 11, the tie-down brackets 85lock the movable frame 11 to the frame 19 to prevent vertical movementof the movable frame during motion of the vehicle over uneven ground.The movable frame 11 has a plurality of tie-down brackets 86 thatcooperate with the tie-down brackets 85 on the frame 19. The forwardlydisposed frame brackets, 85 and 86, are positioned lower than therearwardly disposed frame brackets, 85 and 86, to allow the forwardlydisposed frame brackets 86 on the movable frame 11 to slide under therearwardly disposed brackets 85 of the frame 19 during the initialloading. In the final loaded stage, the brackets 86 are positioneddirectly under the corresponding stationary frame brackets 85.Advantageously, the brackets eliminate excessive noise between frame 11and frame 19 when the vehicle is operating and also has the safetyadvantage of preventing a roll over of the movable frame 11 when loadedon the frame 19.

The movable frame 11 has wheels 56 on the frame 11 so that frame 11 canbe moved relative to the stationary frame 19 prior to engagement. Thewheels 56 are removable when the wheels are off the ground. The wheels56 are removed by removing the hitch pin 113 from pin hole (not shown)in the wheel support tubing 114 and allowing the shaft of front wheelframe 57 to drop down out of the movable frame wheel support tubing 114,then replacing hitch pin 113 in pin hole. The vehicle 13 may bemaneuvered to align to the moveable frame, such that if the wheels 56are used on the rear of the movable frame 11, they are aligned such thatthey track straight and parallel to the lines of the movable frame rails58. This wheel alignment encourages the movable frame 11 to remain inalignment with the frame 19 when loading and off-loading.

Referring now to FIGS. 1, 9, 10, 11 and 13, a pair of chain lockingsystems 10 are rearwardly mounted on the frame 19 and adjacent the rearwheel of the vehicle as each of the chain locking systems 10 comprises asprocket 12, a movable shoe arm 22, a movable shoe 26, a sensing plate32, a locking arm 28, a support member 88 and a pair of main springs 36and 38, attachment bracket 93, slot 120, bolt 110, spring tensioningplate 35 and pin 119. The support member 88 has a first end portion 101and a second end portion 102 and is fixably attached by attachmentbracket 93 to the chassis frame 9. The first end portion has a slot 120best seen on FIG. 13. Fixably attached to the first end portion 101 by abolt 110 is the adjustable spring tensioning plate 35 and fixablyattached to the spring tensioning plate is a pin 119. The pin 119 hastwo ends and each end projects from the side spring tensioning plate 35.The first end has a slot in the pin that the spring 36 is fixablyattached to and the second end is positioned as a pivot for the arm 22with arm 22 positioned in slot 120. The center portion of the supportmember 88 is a bushing 109 that encases the circumference of the axle 14adjacent the outer end. The support member 88 allows axle 14 to rotateinside the bushing 109 additionally supporting the axle 14 by thechassis 9 when the front end portion 25 of the movable frame is beinglifted during initial loading.

The support member 88 allows the axle 14 to rigidly support a stationaryshoe 23. Should the movable frame 11 rise, the roller chain frame 60will rise up to the stationary shoe 23 thereby keeping the chain 83engaged with the sprocket teeth 12. The stationary shoe 23 isadvantageously placed and shaped so that it maintains the tag chain 66or the roller chain 83 on the sprocket. Referring to FIG. 16, thestationary shoe 23 is positioned at an imaginary intersection point thatis defined by the tangential angle of contact between the movable frameand the sprocket. This exact placement allows the movable frame 11 tomaintain a maximum angle during loading, as shown by a pair of tangentlines 117 and 116. The stationary shoe 23 is also shaped so that itfollows these tangent lines and this allows the movable frame 11 torotate through all desired angles on the sprocket. In all cases, thestationary shoe 23 prevents the tag chain 66 and the roller chain 83from skipping off of the teeth on the sprocket 12 by allowing minimumclearance between the stationary shoe 23 and the sprocket 12. Thestationary shoe 23, with the combined strength of the axle 14 and thesupport 88, the frame 11 and a frame attachment bracket 93, prevents themovable frame 11 from rolling sideways off the vehicle should the othersafeties fail.

Referring now to FIG. 13, the sensing/locking arm shaft 40 is rotatablymounted on the second end portion 102 of the support member 88. Thelocking arm 28, the sensing plate 32 and the main spring 38 areco-axially and fixably attached to the shaft 40. Those skilled in theart will recognize that the sensing plate 32 and locking arm 28 could bemanufactured from a single plate. The outer coil end of spring 38 isfixably attached to an attachment bracket 93. The movable shoe arm 22has a first end portion and a second end portion. The first end portionof the shoe arm 22 is urged towards the chain and the second end portionis pivotally attached to the first end portion in slot 120 of thesupport 88 by the pin 119.

Referring now to FIGS. 9, 10 and 11, the moveable shoe arm 22 has aprojection 103 that extends outwardly therefrom. The movable shoe 22 hasa second projection 118 and fixably attached to this projection is theouter coil of the spring 36. The locking arm 28 has a first end portionand a second end portion, the second end portion being fixably attachedto the first end portion of the shaft 40 (FIG. 13). Furthermore, thelocking arm 28 has a groove 31 that is machined into the body. Thegroove 31 is shaped so that when the shoe 22 and the arm 28 are sprunginto a closed position, the groove 31 co-operates closely with theprojection 103 on the shoe arm 22. The arm 28 also has a tab 30 that isshaped such that it pushes chain 66 off of the sprocket 12. The tab 30also redirects the chain 66 back onto the teeth of the sprocket 12. Thesensing plate 32 has a first end portion and second end portion. Thefirst end portion of the plate 32 has a bearing 34 attached thereto andis urged upwards against the bottom side 92 (FIG. 11) of the movableframe rails 58. The second end portion of the plate 32 is fixablyattached to the center portion of the sensing/locking plate shaft 40.

The movable shoe 22 spring tensioning can be adjusted by turning thebolt 110 to loosen the spring tensioning plate 35 and then swiveling theplate which in turn turns the center of the main spring 36. A frontrelease fork 24 prevents the tag chain 66 from wrapping around thesprocket 12 during the initial chain engagement. A rear chain releasefork 18 prevents the tag chain 66 from wrapping around the sprocket 12after the movable frame 11 is lowered to the ground but before thesprockets 12 allow the tag chain ends to drop to the ground.

Referring to FIGS. 3, 4 and 7, during final engagement of the movableframe 11 with the frame 19, a pair of stop plates 68 at the rear endportion 27 of the moveable frame 11 abuts a pair of stop plates 81 inthe rear block assembly 80. Advantageously, the stop plate face 68 isalso covered with UHMW 67 to prevent the rubbing noise of metal on metalwhen the vehicle is moving.

Operation

With reference to FIGS. 1, 8 and 9, the operation of the firstembodiment will now be described. With the movable frame 11 positionedon the ground the operator may back the vehicle 13 up to the movableframe 11. The tag chain 66 is placed onto the sprocket 12. The tagchains 66 are aligned to the rear of the stationary shoe 23 so as toline the end portion 63 of the chains in the same clock position on thesprockets 12. The operator activates the motor 94 from an electricalcontrol box (not shown) which releases an integral motor brake andbegins rotation of the axle 14.

As the sprockets turn, the tag chain 66 tightens and the front-endportion 25 of the movable frame 11 begins lifting off of the ground. Atthis point, the weight of the movable frame 11 is distributed betweenboth of the rear wheel assemblies 56, the ground, the two tag chains 66and the sprockets 12. The tag chain lifting force is transferred 90degrees to the first link 62 of the roller chain 83. Each sprocket 12has about 180° of contact with the tag chain 66. This is sufficientcontact to allow safe lifting or lowering of the movable frame 11. Atthis stage, the front release fork 24 prevents the tag chain 66 fromwrapping around the sprocket 12.

The chain 66 begins lifting the weight of the movable frame 11. The tagchain/locking process remains in place until the weight of the loadedmovable frame 11 is supported by the rear block assembly slide 8. Thisadvantageously eliminates the opportunity of the tag chain 66 slippingoff the sprocket 12 and dropping the loaded movable frame 11. The tagchains 66 are prevented from working off the sprockets 12 by the movableshoes 26 that are positioned directly above the sprocket 12 and are heldin position by the locking arms 28. The chain locking mechanism is apositive tag chain-to-sprocket locking device that reduces oressentially eliminates the possibility of the tag chain 66 being pulledoff the sprockets 12 when the locking arm 28 is in position.

Referring to FIGS. 2, 7, 8, 9 and 10, during the mounting phase of theoperation, the movable frame 11 continues being pulled up and forwardtowards the frame 19 with two tag chains 66 and two roller chain links62 now in contact with sprockets 12. The two frame rails 58 begin toslide over the slides 8. The frame rails 58 and slide 8 take the weightof the front of the movable frame 11, which removes the weight off thetag chain 66, the roller chain frame 60, sprocket 12 and drive axle 14.

Advantageously, as the movable frame 11 moves further forward, theroller chain frame 60 moves under the stationary shoe 23 therebypreventing the movable frame 11 from tipping or rolling off sideways.Furthermore, this prevents the roller chain frame 60 from lifting up toa point where the chain links could slip a tooth on the sprocket 12 andensures that the movable frame cannot fall back off the slides 8. Thisguide system of 58, 8 and 16 maintains the movable frame in a straightline with the stationary frame 19.

At this stage, the operator removes the wheels 56 at the front of themoveable frame 11 to prevent them from interfering with the vehicletires 29.

Referring to FIGS. 9, 10, 11 and 13. As the vehicle 13 has twoessentially identical locking systems 10 mounted rearwardly, only onewill be described in detail.

The front-end portion 25 of the rail 58 contacts the sensing plate 32and pivots the sensing plate 32 forwardly and downwardly. The sensingplate 32 rotates the shaft 40 against the spring tension of the mainspring 38. Rotation of the shaft 40 also pivots the arm 28 forwardly anddownwardly. The groove 31 in the arm 28 pivots clear of the projection103 on the arm 22, thereby releasing the arm 22. As the movable frame 11continues advancing, the sensing plate 32 continues to pivot downwardly,which in turn rotates the shaft thereby moving the arm 28 furtherforwardly and downward and increasing the tensioning of spring 38. Thearm 28 pivots forward and down with the tab 30 on the arm 28 pushing thetag chain 66 forward and off the teeth of the sprocket 12.

Methods other than the sensing plate 32 may be used to sense the frame11 when loading or off-loading and to activate the locking plate 28.This timing and activation may be accomplished electrically by the useof limit switches that sense a lower portion of the surface 92 of therail 58 and in turn the limit switches may control the operation of anelectric or mechanical solenoid or small gear motor that closes or openslocking plate 28.

As the chain 66 is being pushed forward off the sprocket 12, the chain66 contacts the arm 22 which is still in a closed position. The forwardadvancement of the chain 66 pushes the movable arm 22 forward and open,which overcomes the force of the spring 36. The tab 30 of locking arm 28has now pushed the tag chain 66 forward and off the teeth of sprocket 12and tab 30 holds the chain forward and away from the sprocket 12, and inturn the chain 66 holds arm 22 forward and up. With the front of movableframe rail 58 still moving forward, the arm 22 is lifted by the rollerchain frame 60 on the side of the frame rail 58 as the roller chainframe 60 slides under the arm 22. The arm 22 is lifted by the forwardsliding action of the roller chain frame 60 and movable shoe 26 rests onthe top of the frame 60 as it moves forward. With the frame rail 58still advancing, the rail 58 slides over the plate 32 and bearing 34.The bearing 34 rolls along the bottom side 92 of rail 58 for theremainder of the operation.

The tab 30 on the arm 28 holds the tag chain 66 forward and away fromthe sprocket 12, while the frame rail 58 advances. This prevents thechain 66 from hanging or “welding” to the sprocket 12. With the forwardmovement of the frame rail 58, the tag chain 66 is moved forward andaway from the tab 30.

Advantageously, slot 31 is so machined that when the movable shoe armprojection 103 is in a locked position with the locking arm slot 31,there is a space between the chain 66 and arm 22 to prevent excessivewear.

For operation of the chain locking system 10 in reverse, the processdescribed above is essentially reversed. During rearward movement of theframe 11, for example in the off-loading procedure, the main springs 36and 38 urge the arm members 22 and 28 into a closed position when theloose tag chain 66 re-engages the sprocket 12. The shoe 23 that isattached to the first end portion 101 of the support member 88 preventsthe chain from skipping the teeth on the sprocket 12. Furthermore, thestationary shoe 23 prevents body rollover when off-loading the movableframe 11 from the stationary frame 19. In the fully opened position, theshoe 23, and the arms 22 and 28 allow the chain 83 to move freely withthe sprocket 12. As the movable frame 11 moves rearward with the tagchain 66 approaching the sprocket 12, the tag chain 66 contacts thelocking arm tab 30. The roller chain frame 60 begins to slide from underthe movable shoe 26 and arm 22, and the movable shoe 26 and the arm 22pivots down and contact the top of the tag chain 66 and tag chain 66 ispressured down against the tab 30. With the sensing plate 32 followingthe contour of the rail 58, the tab 30 pivoting down and rearward and tothe closed position allows the tag chain 66 to lay onto the teeth of thesprocket 12. The tag chain 66 is urged on to the teeth of the sprocket12 by the spring-tensioned arm 22. With the tag chain 66 engaging on thesprocket 12, the groove 31 of the spring-tensioned locking arm 28 pivotsover projection 103 on the moveable arm 22 and the locking system isagain closed and locked.

The stationary shoe 23 is positioned such that at any angle of loading,the shoe 23 acts as a secondary hold for the movable frame 11 to thestationary frame 19 and thereby positively locks the roller chain 83 tothe teeth of the sprocket 12. The stationary shoe 23 also acts as asecondary hold of the tag chain 66 to the teeth of the sprocket 12during lifting and lowering of the front end portion 25 of the movableframe. Advantageously, if the locking system 10 were to fail or a loadwas loaded or off-loaded with the system unengaged, the tag chain 66would still be secured by the stationary shoe 23.

Referring to FIGS. 14, 17, 18 and 19, with the frame 11 still movingforward and the rear wheels 56 still on the ground, the movable framecross member 65 moves over the elevatable support 17. With the rearwardportion of the elevatable support 17 rotatably attached to the axle 14,and if the forward portion of the UHMW 50 on top of slide rail 44 is toohigh for the slot 75 to clear, the slide rail 44 will be pushed, in turnpivoting the elevatable support 17 down by the slot 75 and by the weightof the movable frame 11. A lift plate 87 enters the rearward disposedend of the channel 54 and alignment plate 73 slides over top of theslide rail 44. If the slide rail 44 is still too high, the alignmentplate 73 pushes on the slide rail 44 and the elevatable support 17pivots further down. If the elevatable support 17 is low, the lift plate87 slides along the inside top lip of the channel 54 and lifts andpivots the elevatable support 17 upwardly as the movable frame movesforward. The lift plate 87 slides along and under a tapered internalramp 33 and lifts and pivots the elevatable support 17 higher. With theelevatable support 17 height finely adjusted, the rail 44 aligns withthe receiver 72. The movable frame 11 slides further forward and thefront portion of the receiver 72 slides and interlocks over the reardisposed portion of the elevatable support rail 44, which is coated withUHMW on both sides. With further forward movement of the movable frame11, the receiver 72 slides further forward over the rail 44.

The elevatable support guide system 59 along with the slot 75, the liftplate 87 and the alignment plate 73 allow various lengths of frames tobe loaded on the same stationary frame. When the frame 11 is off-loadedthe elevatable support 17 maintains this angle. When a different lengthof frame 11 is on-loaded the angle of loading changes. The elevatablesupport may be re-adjusted by the above components allowing this newreceiver to align with the elevatable support with no manual laborrequired.

As best seen in FIG. 21, the movable frame 11 is balanced above the rearblock assembly slide 8 whereupon only the slides 8 on the rear blockassemblies 80 are in contact with rails 58. The receiver 72 isinterlocked with the rail 44 and the movable frame rails 58 arestraddling the rear portion of the stationary frame rails 16. As themovable frame 11 is moved forward so that the center of gravity andweight is passed over the slides 8, the weight is transferred from therear wheel assemblies 56 to the elevatable support 17. The elevatablesupport 17 allows the weight to drop down onto the stationary frame 19in a controlled manner by the resistance of the hydraulic cylinder 46,flow restrictors and valves. The movable frame 11 is eased down onto thestationary frame 19 with the movable frame rails 58 resting on top andstraddling the rails 16, thereby preventing lateral movement of themovable frame 11 when travelling (FIG. 12). The tag chains 66 are pulledup onto the storage tracks 84 as the movable frame 11 continues forward.The storage area on top of the roller chain frame 60 is only used whenthe movable frame 11 is off the vehicle 13.

One skilled in the art will understand that the storage track 84 may beomitted. The top of the roller chain frame 60 along with the side bar 79on the movable frame 11 may be used in place of the storage track 84.The side bar 79 makes a storage track for the tag chain 66. The bar 79moves through the stationary shoe groove 121 (FIG. 13) when the movableframe 11 is loaded or off-loaded. This track may be necessary whenloading and off-loading because when the movable frame 11 is moving ontop of the stationary frame, the hanging tag chain 66 may catch, or hangup, on the vehicle suspension on parts of the chassis 9. In loading theoperator may be required to manually place the tag chain 66 into thestorage track roller chain frame 60. In off-loading, the tag chain 66may be removed from the top of the roller chain frame 60 by the movableshoe 26. With the movable shoe 26 on the top of roller chain frame 60the shoe 26 pushes the tag chain 66 off of the roller chain frame 60 asthe movable frame moves in rearward direction.

As best illustrated in FIGS. 2, 5, 6, 11, 12 and 21, the stop plates 68prevent the movable frame from being pushed forward into the cab of thevehicle 13. Advantageously, the stationary shoes 23, the movable shoearms 22, the rear upper tie down brackets 85 and the rear lower tie downbrackets 86, the receiver 72 and the elevatable supports 17, are soconfigured that they prevent the movable frame stop plates 68 fromlifting over the stop plates 81 in an accident. The manual lockingmechanism 82 is used to lock the movable frame 11 in the loadedposition. Moving the handle 89 into the locked position causes the pins71 and 78 to move into the locking pin holes in the movable frame 11.

In order to remove the movable frame 11 same procedure is used exceptthat the motor 94 is activated in the reverse direction.

Referring to FIGS. 2, 6, 7, 14, 17 and 18, the movable frame 11, mayhave fender components that hang lower and in front of the rear vehicletires 29. The ramp system for on and off-loading of a fender bodycomprises a pair of lower fender slide frames 95, a pair of slide posts69 and a pair of roller posts 91 that are located on the movable frame11. A pair of ramps 90 are correspondingly located on the frame 19. Theframe components protect the fenders 99 of the box 105 of the movableframe 11 when loading and off-loading. One skilled in the art willrecognize that there are many types of fender bodies, for example, astandard fleet slide or step side pickup box body, a utility box body,catering truck bodies, motor home bodies and passenger bodies to nameonly a few.

The lower fender slide frames 95 protect the fenders 99 of the body. Thefender slide frames 95 is slightly lower than the fenders 99. The slideframe 95 is supported and attached to the movable frame cross members115 and the cross members 77. The lower fender frames 95 shown, work asa slide system that slides across the top of the rear tire 29 whenloading or off-loading. The balance point of the movable frame 11 at thetime of loading or off-loading determines if the slides 95 contact withthe tires 29.

The slide posts 69 slide up or down the topside of the rearward angledportion of the ramps 90. The slide posts 69 are shorter than the rollerposts 91 located forward therefrom on the frame 11. The bottom end ofthe shorter slide posts 69 is high enough to contact the top side of thesloped rear section of the ramps 90 when the frames 95 are slidingforward on the tires 29. The front portion 25 and the roller posts 91 ofthe frame 11 are raised as the slide posts 69 slides forward and up theramps 90. The longer roller posts 91 are raised to a position where theycontact the top sides of the sloped rear sections of the ramps 90.

The short slide posts 69 allow the most rearward end of the slopedsection of ramps 90 to be high above the tires 29 allowing necessaryclearance from tires 29 to ramps 90.

The longer roller posts 91 lifts the frame 11 high enough so as tomaintain necessary clearance between the front of the wheel wells 98 andthe tires 29. Depending on the weight, the balance point and the speedat which the frame 11 is on or off-loading, the setting of the controlsof the hydraulic cylinder 46, plus the vehicle chassis suspension, slidepost 69 may or may not be used.

For off-loading, the slide posts 69 carry the movable frame 11 when theroller posts 91 roll off of the sloped rear section end of the ramps 90to a point where either gravity tilts the movable frame 11 up or theframes 95 contacts the tires 29. The slide posts 69 could also beequipped with rollers.

The roller posts 91 carry the movable frame 11 as it rolls up and downthe ramps 90 during loading or off-loading. The roller posts 91 carrythe load weight at different times depending upon the weight, balancepoint and speed at which the frame 11 is on or off-loading, the settingof the controls of the hydraulic cylinder 46, plus the vehicle chassissuspension.

By eliminating the rear sloped section of the ramps 90 and extending thehorizontal section of the ramps 90 rearwardly away from the rear of tire29, the slide post 69 and the lower fenders' slide frames 95 may beeliminated, providing the design of the vehicle chassis 9 is such thatadequate clearance is maintained between the top of the tires 29 and theramps 90 when the vehicle is loaded and in motion. One skilled in theart would recognize that the balance point is such that the roller posts91 would be positioned over the ramps 90 when the center of gravity ofthe fender body 105 is moved over the rear block assembly slide 8.

If the fully loaded movable frame 11 begins to off-load, the rollerposts 91 come into contact, rolling rearward and upward on the top sideof the front angled portion of the ramps 90, thus lifting the frontportion 25 of the movable frame 11. The rearward portion 27 of the rails58 slide and pivot on the rear block assembly slides 8. The movableframe 11 and the receiver 72 lift the elevatable support 17 up as thereceiver 72 slides along the slide rail 44.

Referring to FIGS. 6, 17 and 18 with the front portion 25 of the movableframe 11 moving up, the front of fender walls 98 clear the top of thetires 29 and the roller posts roll along the horizontal section of theramps 90. The roller posts 91 roll rearward and down the rear portion ofthe ramps 90. With the roller posts 91 rolling to the end of the ramps90 the shorter slide posts 69 contacts the ramps 90 and as the movableframe 11 is moved rearward the slide posts 69 slides rearward and downthe ramps 90. The front-end portion 25 of the movable frame 11 continuesmoving rearward and down, the lower fender slide frames 95 contacts thetop of the tires 29. The weight of the front end portion 25 of themovable frame 11 is removed from the slide posts 69 and ramps 90 to thelower fender slide frames 95 and the top of the rear tires 29. The framesliding rearward with the weight of the front portion end 25 of themovable frame 11 on rear tires 29 and the weight of the rear end portion27 of movable frame 11 on the rear block assembly slides 8 and with thereceiver 72 sliding on the elevatable support rail 44, the point ofbalance of the movable frame slides over the rear block assembly slides8 and the front end portion 25 of the movable frame 11 tilts upward andrearward. With the receiver interlocked with the elevatable support rail44 the tilting action lifts the elevatable slide support. The speed oflift action is controlled by the scissor arms 15 and 37, the hydrauliccylinder 46 and its associated hydraulic flow controls and valves. Themovable frame 11 tilting action occurs at the time the point of balanceof the movable frame 11 slides over the rear block assembly slides 8.The tilting action timing varies depending on the distribution of thepayload weight of the movable frame 11.

In on-loading of the moveable frame 11, the procedure is reversed.

1. A loading apparatus for mounting a movable frame on a stationaryframe, wherein; there is an elevatable support member mounted on thestationary frame, the elevatable support member having a first endportion and a second end portion, the second end portion of theelevatable support being mounted to the stationary frame for pivotalmovement with respect to the stationary frame about an elevatablesupport axis to provide an adjustable angle of the elevatable support;and a lift action control mechanism mounted on the stationary framecooperates with the elevatable support member to modulate movement ofthe elevatable support about the elevatable support axis; characterizedin that: a drive is co-axially arranged with the elevatable supportabout the elevatable support axis; the drive is adapted for connectionwith the moveable frame, so that the drive may slidably move themoveable frame onto and off of the elevatable support and the stationaryframe, while the lift action control mechanism permits the angle of theelevatable support to adapt about the elevatable support axis so thatthe elevatable support slidingly engages the movable frame.
 2. Theapparatus of claim 1, wherein movement of the movable frame powered bythe drive adapts the angle of the elevatable support so that theelevatable support slidingly engages the movable frame.
 3. The apparatusof claim 2, wherein the drive is a sprocket powered by an axle, and theelevatable support is rotatably attached to the axle.
 4. The apparatusof claim 2, wherein there is an interconnection between the elevatablesupport and the moveable frame, during sliding movement of the movableframe, so that the movable frame adapts the angle of the elevatablesupport through the interconnection.
 5. The apparatus of claim 1,wherein the drive is a sprocket powered by an axle, and the elevatablesupport is rotatably attached to the axle.
 6. The apparatus of any oneof claims 1 through 5, wherein the lift action control mechanismcomprises a damping element to controllably resist the movement of thefirst end portion of the elevatable support member towards a raisedposition and to control movement of the first end portion of theelevatable support towards a lowered position.
 7. The apparatus of claim6, wherein the damping element is powered to control the movement of thefirst end portion of the elevatable support member towards a raisedposition and to control movement of the first end portion of theelevatable support towards a lowered position.